Stethoscope

ABSTRACT

A stethoscope for improved auscultation providing small bell and diaphragm chest pieces selectively interconnectable to an air column channel having binaural branch ear tube components leading to the earpieces. Sound losses and attenuation are minimized by avoidance of abrupt changes in the volume and flow direction for the air columns and by a pivoting selector permitting direct flow connection of either chestpiece to the earpieces through a shorter air channel. Earpieces are movable to adjusted positions with respect to the ear tubes for improved fit, and the ear tube components are provided with tension adjustment features and are further pivotally mounted to facilitate storage.

United States Patent [72] inventor Abe Ravln 45 South Dahlia Street,Denver, Colo. 80222 [21] Appl. No. 828,507 [22] Filed May 28, 1969 [45]Patented Dec. 28, 1971 [54] STETHOSCOPE l 1 Claims, 1 1 Drawing Figs.[52] US. Cl 181/24 [51] Int. Cl A6lb 7/02 [50] Field of Search 181/24[56] References Cited UNITED STATES PATENTS 862,016 7/1907 Port 181/24882,700 3/1908 Lewis 181/24 1,466,825 9/1923 Foord 181/24 2,258,74310/1941 Dax 131/24 3,169,600 2/1965 Thomas... 181/24 3,295,631 l/l967Machlup 181/24 3,366,198 1/1968 Littmann 181/24 Primary Examiner-StephenJ. Tomsky Attorney-C. B. Messenger ABSTRACT: A stethoscope for improvedauscultation providing small bell and diaphragm chest pieces selectivelyinterconnectable to an air column channel having binaural branch eartube components leading to the earpieces. Sound losses and attenuationare minimized by avoidance of abrupt changes in the volume and flowdirection for the air columns and by a pivoting selector permittingdirect flow connection of either chestpiece to the earpieces through ashorter air channel. Earpieces are movable to adjusted positions withrespect to the ear tubes for improved fit, and the, ear tube componentsare provided with tension adjustment features and are further pivotallymounted to facilitate storage.

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INVENTOR. A BE RA VIN ATTORNEY STETIIOSCOPE BACKGROUND OF THE INVENTIONStethoscopes have been used beneficially for many years. Knowledgeconcerning body and other functions that may be observed and diagnosedby auscultation has expanded substantially. Many difierent types ofstethoscopes have been used, and various designs have been introduced toimprove the utility and handling characteristics of stethoscopeinstruments. Regrettably, the sound transmission characteristics of somemodern day stethoscopes is not an improvement. Undoubtedly there arebenefits to be derived from the provision of a stethoscope thattransmits sound with improved efficiency and that is also convenient tostore, handle and use.

SUMMARY OF THE INVENTION The present invention provides a stethoscopesystem utilizing two chest pieces that may be selectively interconnectedwith the ear tubes and ear pieces of a binaural stethoscope. The chestpieces are disposed on a single assembly, and a pivoting or rotatableselector valve is provided to interconnect either the bell-shaped or thediaphragm chest piece to the air channels of the ear tube and earpieces. The valve selector is specifically designed so that the pickupsound pulses from the chest piece being used will be transmitteddirectly and without any severe angular bends to the ear piece. Soundattenuating bends or severe changes in the total cross-sectional area ofthe air column are avoided to minimize interferences with the soundmovement patterns in the air column interconnecting the selected chestpiece and the ear pieces. The selector valve is held efficiently in itsselected position by detent means. The

valve further provides surfaces facilitating manipulation of the chestpieces at time of use.

In a separate embodiment of the invention the ear tubes and ear piecesmay be pivoted for more convenient storage and usage. The ear piecesthemselves are likewise movable to angular positions so that betterinstrument-to-ear engagement is possible.

In a further embodiment of the invention, bell chest pieces of differentsize are provided for selective use in a design additionally providing adiaphragm type chest piece adapter. In such design all the bells anddiaphragm components are directly connected to the ear tubes without useof an intermediate selector valve. Tension adjustment devices areprovided to assure better ear contact pressures.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an assembly illustration inpartial section illustrating features of a first embodiment of theinvention,

FIG. 2 is an elevation showing use of stethoscope chest pieces made inaccordance with this invention,

FIG. 3 is a cross-sectional elevation showing features of a selectormechanism initially connected to a bell-shaped chest piece,

FIG. 4 is a side elevation similar to that of FIG. 3 showing theselector valve assembly of the FIG. 3 device in a diaphragm chest piececonnecting position,

FIG. 5 is a partial cross-sectional elevation taken along the line 55 ofFIG. 4,

FIG. 6 is a cross-sectional elevation through a separate embodiment ofthe invention,

FIG. 7 is a cross-sectional elevation showing the FIG. .6 embodiment inalternate position and with an additional diaphragm adapter piece,

FIG. 8 is an elevation in partial section showing features of a separateembodiment of the invention,

FIG. 9 is a perspective view showing the FIG. 8 embodiment in a storageposition,

FIG. 10 is a partial elevation showing features of an alternate ear tubeand tension adjustment assembly, and

FIG. 11 illustrates an alternate adjusted position for the assembly ofFIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first preferred embodiment ofthe invention is shown in FIGS. 1-5. In FIG. I an assembled stethoscope11 is illustrated which includes ear pieces 12, ear tubes 13 ofsymmetrical configuration, a spring yoke 14 for holding the head framesin engaged position on a user's ears, and an air tube 16 which includesa main tube 17 and separate binaural branches 18 disposed at the eartube rear ends thereof. At the opposite end the tube 16 is joined to astandpipe 19 of chest piece selector assembly 21. The standpipe 19 maybe moved into selective direct communication with either the bell chestpiece 22 or a diaphragm chest piece 23. End grips 24 are provided at thelateral ends of the chest piece selector 21 to be conveniently grippedby the thumb 26 and forefinger 27 of the user so that either the bell 22or diaphragm 23 may be conveniently held with a proper engaging pressureagainst the body of a patient.

In the illustration of FIG. I it should be noted that the inner passage29 of the standpipe 19 is of the same cross-sectional area as theinternal passage 31 of the air tube 16. At the transition or Y-branch 32the air passage is split to provide binaural tubes 18, but at this pointthe cross-sectional area of the air column 31 in the tube 16 is equal tothe total cross-sectional area of the separate channels 33 in thebinaural branches 18. Again, the cross-sectional area of each binauralbranch channel 33 is equal to the inner cross-sectional area of thepassages 34 in the ear tube pieces 13. This cross-sectional size iscontinued at the ear piece 12 where the openings 36 are of sizecorresponding to the passages 34. With this arrangement the air columnpassages from the ear to the chest piece are of regulated size, andright-angle or severe bends are prevented that would tend to attenuatethe sounds that are to be transmitted.

Detailed features of the chest piece selector 21 are shown in FIGS. 3, 4and 5. In these figures it is seen that a main body 41 of externalcylindrical or barrel-type configuration encloses a cylindrically formedvalve element 42 into which the end of the standpipe 19 extends. A cutslot 43 is provided along a circumferential surface of body 41 so thatthe standpipe 19 and attached valving member 42 may be pivoted from theposition shown in FIG. 3 to that shown in FIG. 4. A counterbore 44 isprovided in the body of the valve disk or cylinder 42, and a socket pinor plunger 46 is reciprocally received in such bore. A resilient elementor O-ring 47 is disposed in the bottom of the bore 44 so that the socketplunger 46 can move reciprocally against the resilience of the O-ring47. In positions aligned with the bell 22 and the diaphragm 23, detentsockets 48 and 49 are provided. Accordingly, when the valve is inposition aligned with the bell or diaphragm, the plunger 46 will beextended into a detent socket to hold the valve in desired position. Ateach of these positions, as illustrated in FIGS. 3 and 4, a central bore51 in the plunger 46 will be properly aligned with and in directcommunication with the central bore 29 of the standpipe 19 and with thecentral passage openings 52 and 53 of the bell and diaphragm chestpieces 22 and 23.

Each of these passages 52 and 53 has a widening or flared cross sectionaway from the valve 42. This flared or trumpet shape is preferablycontinued into the bore 51 for the plunger 46. This arrangement forstarting the flared shape within the confines of the valve structureitself makes it possible to further shorten the length of the total aircolumn between the patient and the physician s ears. The potentialshortening provided by this feature, while significant, is notequivalent however to the major shortening of the air column that isrealized through provision of the selector valve arrangement shown inFIGS. 14. The described arrangement makes it possible for the physicianto place the selected chest piece directly on the patient without anyintervening bends being necessary in the air tube 16 due to an offset orangular positioning of the chest piece being used with respect to theaxis of the air tube itself.

While the bell chest piece 22 is provided with a desirable trumpetshape, the diaphragm chest piece 23 for this embodiment of the inventionis of relatively conventional construction. As in previous stethoscopes,this chest piece 23 is of an overall flat disk shape with a backplate 54extending outwardly from a main support hub 56. A diaphragm engagingbezel 57 is threaded on the backplate 54 to hold the diaphragm 58 inposition occluding the passage 53. For alternate usages, the diaphragm58 and holder bezel 57 may, of course, be removed to provide directcommunication to the passage 53 and, through valve component 42, to thestandpipe 19. A shallow shoulder or ring 59 is provided on the bezel 57so that the diaphragm 58 may be selectively held away from directcontact with the patients skin for some auscultation operations. Forother uses the application of a slight pressure will cause adequatedeformation of the patients flesh to bring the diaphragm into directcontact therewith.

The chest piece selector assembly 21 shown in FIGS. 1-5 is particularlywell adapted for use with an alternate type of head frame assembly asshown in FIGS. 8 and 9. Here the air tube 16 and its binaural channels18 are connected to ear tube pieces 63. A tension spring assembly 64 isdisposed between the spaced apart ear tubes 63 to provide a tensionforce tending to hold the ear tubes and associated ear pieces 62 inposition for use. The tension assembly 64 includes a spring 66 disposedwithin the housing 67 with its otherwise free end 68 engaged to anadjusting mechanism 69. When the knurled knob of the adjusting mechanismis rotated on the anchor screw 71, the tension in spring 66 will beincreased or decreased. A spacer 72 is provided below the tensionadjusting mechanism 64, and collars 73 on the ear tube pieces 63 are inengagement with the spacer 72. The cooperative form of the collars 73and the spacer 72 permits rotation of the ear tubes 63 about two axes ofrotational freedom. This freedom makes it possible to insert and removethe ear tubes from positions of ear contact, and it alternativelypermits the ear tubes to be rotated to a storage position as shown inFIG. 9. When in the collapsed storage position shown in FIG. 9, theentire stethoscope can, of course, be conveniently stored in aphysicians pocket or the like.

The ear pieces 62 illustrated in FIG. 8 incorporate a furtherimprovement. As shown, the ear tube pieces 63 engage a pivot mount 74.Ear piece 62 is snapped into a receptacle 76 provided by the pivot mount74, and ear piece 62 can then be rotated in such receptacle to alternatepositions. As the ear piece is rotated, its bent shape as illustratedwill allow orientation of the ear piece 62 at various adjusted angles.This angular position can then be separately adjusted by the user of thestethoscope to assure proper alignment of the air column passage 86 andthe ear piece 62 with the air channels in the users ear. Misalignment atthis user-to-instrument interface has previously contributed todecreased sound reception with some previous stethoscope configurations.The rotary and pivoted combination provided by the ear pieces 62 and eartubes 63 avoids previously necessary bending of stethoscope ear tubes toaccommodate users having distinctive ear configurations.

A further embodiment of the invention is presented in FIGS. 6 and 7where a modified type of chest piece is shown. I-Iere chest piece 81 hasa nonpivoting body 82 adapted to receive standpipe 19. The standpipecommunicates directly with the trumpet shaped passage 83 of a smallerbell chest piece 84. A larger bell component 87 is reciprocally mountedon the external surface of the bell 84, and it may be moved to alternatepositions, as shown in FIGS. 6 and 7. In either posi tion it will beheld in its selected position by a spring loaded pin 88. When the largerbell component 87 is moved forwardly, as shown in FIG. 7, contact withthe patient is made by the enlarged ring 89. With the enlarged area ofcontact different sounds may be more readily observed in the patient. Ininstances where a diaphragm reading is still thought to be advantageous,a separate diaphragm adapter 91 may be engaged to the large bellcomponent 87. Diaphragm adapter 91 is preferably made of resilientmaterial so that it will be held in assembled relation by its ownresilience. As in the previous configuration, a raised ring 92 isprovided on diaphragm adapter 91 so diaphragm 93 may be selectivelyengaged or not engaged with the patients skin.

A separate type of tension assembly 94 is shown in FIGS. 10 and 11. Thisassembly is used to increase or decrease the holding pressure exerted bythe ear tubes to maintain the ear pieces 12 in connection with thestethoscope user's ears. Tension assembly 94 also makes it possible foran ear tube 63 to be pivoted or turned to a storage position asoriginally shown in FIG. 9. Tension assembly 94 includes a main springelement extending between the ear tube pieces 63 and providing loops 99that loosely engage the ear tubes 63. The main spring element 90 exertsan initial spring force tending to hold the ear pieces 12 in an at-restposition where the ear pieces would be closer together than the ears ofa normal user. When the stethoscope is to be used, the ear pieces will,accordingly, be spread apart, and the spring 90 will exert a forcetending to hold the ear piecesengaged in the users ears.

Adjustments in this tension force may be made by changing the relativepositions of the main spring 90 and an auxiliary spring 95. Spring 95 isprovided with end clips 96 which loosely engage main spring 90 to permitrelative reciprocal movement to alternate positions as illustrated inFIGS. 10 and 11. A threaded adjustment is provided to make such positionchanges. This adjustment includes a threaded stem 97 engaged to the mainspring 90 and a knurled nut 98 rotatably mounted with respect toauxiliary leaf spring 95. With this tension adjustment assembly thepressure exerted on the users cars by the ear pieces 12 may be changeduntil a best sound transmitting and instrument retention result isobtained. For this embodiment of the invention the main spring element90 operates as a spacer with the auxiliary spring 95 providing the majorchanges in the ear engaging pressure.

All embodiments of the invention incorporate features which satisfy themajor objectives in the stethoscope art. Through provision of directlyaligned sound passages and further through provision of assemblies wherethe divergent shape of a bell or other chest piece component iscontinued into the selector mechanism itself, the overall length of thesound passages or air columns between the pickup component and the usersear may be substantially shortened. With the shorter air columns abetter sound transmission and lessened sound attenuation is realized.Further, the direct alignment of sound passages extending outwardly fromthe pickup component in a position normal to the patient contacting lipsurfaces of the pickup components helps to prevent inadvertent contactswith the patients or the physicians person or clothing. Such undesirablesupplementary contact in other stethoscope designs often tends to muffleor distort the sound impulses being transmitted. Such contact furthercan be a source for the introduction of auscultation disturbingbackground noises.

In connection with the preservation of good sound signals, the provisionof finger grips 24 is likewise of importance. Not only do these elementsmake it easier to properly position and hold the instrument, but theyalso prevent sound attenuation due to finger contact on the soundcollecting and carrying bell pieces.

With the provision of stethoscopes incorporating the foregoing featuresand various combinations of such features improved auscultation will bepossible.

I claim 1. A binaural stethoscope for use by individuals in connectionwith the examination of patents comprising ear tubes, ear pieces on saidear tubes for engagement with the user's ears, a chest piece assembly, atube interconnecting said chest piece and ear tubes, a plurality ofpatient contacting sound pickup components disposed at alternatenonaxial positions on said chest piece with each of said componentsproviding a bore sound passage of straight axis therethrough, patientcontacting surfaces for each of said components with said surfaces beingdisposed at positions normal to the position of said sound passages, andselector means having a straight axis sound passage therethrough foralternately interconnecting any of said pickup components to said tube,said pickup component and selector means being cooperatively arrangedwhereby all of the sound passages therethrough are directly aligned atperiods of use to minimize attenuation of the auscultation sound signalsthat are to be observed.

2. Structure as set forth in claim 1 wherein the selector means isinclusive of a rotary element with the sound passage therethrough havingan initial flared shape and wherein the sound passage of said rotaryelement may be selectively aligned with and interconnected to the soundpassages of alternate sound pickup components.

3. Structure as set forth in claim 1 wherein said interconnecting tubeprovides a sound passage therethrough with said tube passage beingaligned at periods of use with the sound passage of the selected pickupcomponent and said selector means whereby the total length of soundchannels from ear piece to pickup component is minimized.

4. Structure as set forth in claim 1 and further comprising a spacer forengaging said ear tubes, a resilient member likewise engaging said eartube, and means for adjusting the force exerted by said resilient memberwhereby the engaging pressure for said ear pieces may be adjusted.

5. Structure as set forth in claim 4 wherein said resilient member is aspring.

6. Structure as set forth in claim 4 wherein separate ear tube piecesare used and wherein the engagement between said ear tube pieces andspacer permits rotation between said ear tube pieces and spacer wherebysaid ear tube pieces may be moved to alternate positions for use andstorage.

7. Structure as set forth in claim 1 and wherein said ear pieces aremovable whereby the angular positioning of said ear pieces may beadjusted.

8. Structure as set forth in claim 7 wherein a pivot mount is providedto facilitate movement of said ear pieces.

9. In a stethoscope construction having ear tubes, ear pieces and aflexible interconnecting tube, a chest piece assembly comprising smalland large sound pickup components disposed at nonaxial positions witheach of said components providing a straight bore sound passagetherethrough, patient contacting surfaces for each of said componentswith said surfaces being disposed at positions normal to the position ofsaid sound passages, selector means having a straight axis soundconducting passage therethrough and adapted for interconnection to saidsound pickup components, and means for selectively moving either of saidpickup components into position for use and application to a patient'sskin with said selector means, the sound conducting passagestherethrough and the sound passages of the selected pickup componentbeing directly aligned and in position normal to the patients skinwhereby sound attenuation due to angular passages and patient or usercontact with stethoscope elements other than the contact surfaces isminimized.

10. Structure as set forth in claim 9 and further comprising a diaphragmadapter for application to the large sound pickup component.

11. Structure as set forth in claim 9 wherein the sound passages throughsaid pickup components are of flared shape and wherein the selectormeans is inclusive of a rotary element with the sound passagetherethrough having an initial flared shape for alignment with the soundpassages of said pickup components.

1. A binaural stethoscope for use by individuals in connection with theexamination of patents comprising ear tubes, ear pieces on said eartubes for engagement with the user''s ears, a chest piece assembly, atube interconnecting said chest piece and ear tubes, a plurality ofpatient contacting sound pickup components disposed at alternatenonaxial positions on said chest piece with each of said componentsproviding a bore sound passage of straight axis therethrough, patientcontacting surfaces for each of said components with said surfaces beingdisposed at positions normal to the position of said sound passages, andselector means having a straight axis sound passage therethrough foralternately interconnecting any of said pickup components to said tube,said pickup component and selector means being cooperatively arrangedwhereby all of the sound passages therethrough are directly aligned atperiods of use to minimize attenuation of the auscultation sound signalsthat are to be observed.
 2. Structure as set forth in claim 1 whereinthe selector means is inclusive of a rotary element with the soundpassage therethrough having an initial flared shape and wherein thesound passage of said rotary element may be selectively aligned with andinterconnected to the sound passages of alternate sound pickupcomponents.
 3. Structure as set forth in claim 1 wherein saidinterconnecting tube provides a sound passage therethrough with saidtube passage being aligned at periods of use with the sound passage ofthe selected pickup component and said selector means whereby the totallength of sound channels from ear piece to pickup component isminimized.
 4. Structure as set forth in claim 1 and further comprising aspacer for engaging said ear tubes, a resilient member likewise engagingsaid ear tube, and means for adjusting the force exerted by saidresilient member whereby the engaging pressure for said ear pieces maybe adjusted.
 5. Structure as set forth in claim 4 wherein said resilientmember is a spring.
 6. Structure as set forth in claim 4 whereinseparate ear tube pieces are used and wherein the engagement betweensaid ear tubes pieces and spacer permits rotation between said ear tubepieces and spacer whereby said ear tube pieces may be moved to alternatepositions for use and storage.
 7. Structure as set forth in claim 1 andwherein said ear pieces are movable whereby the angular positioning ofsaid ear pieces may be adjusted.
 8. Structure as set forth in claim 7wherein a pivot mount is provided to facilitate movement of said earpieces.
 9. In a stethoscope construction having ear tubes, ear piecesand a flexiBle interconnecting tube, a chest piece assembly comprisingsmall and large sound pickup components disposed at nonaxial positionswith each of said components providing a straight bore sound passagetherethrough, patient contacting surfaces for each of said componentswith said surfaces being disposed at positions normal to the position ofsaid sound passages, selector means having a straight axis soundconducting passage therethrough and adapted for interconnection to saidsound pickup components, and means for selectively moving either of saidpickup components into position for use and application to a patient''sskin with said selector means, the sound conducting passagestherethrough and the sound passages of the selected pickup componentbeing directly aligned and in position normal to the patient''s skinwhereby sound attenuation due to angular passages and patient or usercontact with stethoscope elements other than the contact surfaces isminimized.
 10. Structure as set forth in claim 9 and further comprisinga diaphragm adapter for application to the large sound pickup component.11. Structure as set forth in claim 9 wherein the sound passages throughsaid pickup components are of flared shape and wherein the selectormeans is inclusive of a rotary element with the sound passagetherethrough having an initial flared shape for alignment with the soundpassages of said pickup components.